منابع مشابه
Issues in Conservation
Coyotes (Canis latrans) are lethally controlled throughout the range of Greater Sage-Grouse (Centrocercus urophasianus) and it has been suggested that such control may benefit sage-grouse. However, the perceived benefits of control are based on the direct effects of coyotes on sage-grouse and largely ignore potential indirect interactions. Here, we summarize some of the evidence for direct effe...
متن کاملCurrent Issues in Cancer
In the narrowest sense radiotherapy is a treatment almost exclusively used in managing cancer and based on the use of ionising radiation. In practice, however, the scope of the subject is broad (box 1) as management decisions relating to cancer must be made in the context of a thorough appraisal of the tumour and patient. Tumours are characterised by histogenesis and morphology, and, increasing...
متن کاملConservation of Charge and Conservation of Current
Version 3: typos corrected and a section is added " Why does this matter? " (see p. 10)
متن کاملIssues in Ecotourism and Resource Conservation
Is ecotourism merely a novel ‘saleable’ label for what travelers and their agents have been doing all along? Or is it “a new alternative for sharing cultures and ecosystems based on. . noble objectives” [18]? As an arena in which “corporate tenets and conservationist ideals are interwoven’ [47], ecotourism may continue to elude concrete definition. However, analysis of the benefits and costs of...
متن کاملCurrent issues in perinatal epidemiology.
The main national data sources for perinatal epidemiology are birth and death certificates, yet routinely linked birth and death certificate data are still not available in the U.S. Completeness and quality of the reporting of perinatal events should be considered in examining trends over time and between jurisdictions. The U.S. has experienced a marked decline in its infant mortality rate, but...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Nature
سال: 1981
ISSN: 0028-0836,1476-4687
DOI: 10.1038/289350a0